The 41-year-old actressstopped by E!'s Chelsea Lately Monday, where she chatted with host Chelsea Handler about her latest project, The Body Book. "I'm a science nerd," Diaz, 41, explained. "I like to know why things work the way they do. I thought that the body was probably the most important thing to understand how it works since we all have one, and we don't really know that much about it."

Though Diaz teased Handler about her dieting habits, she complimented the comedienne's physique. "I know that you care about it and that you take care of it, and that makes me happy," the star said.

"Will somebody tell that to my body?" Handler joked.

Diaz went on to discuss the dangers of habitual smoking ("One cigarette every once in awhile is not going to kill you," the Charlie's Angels star claimed) and consuming sugar-free soda ("Nothing's for free. My mama taught me that real early," she said of diet drinks) before talking about vagina health.

Opening up Diaz's book, Handler said, "There's a diagram of your labia, and for me, the vagina is such an integral part of the body." The blonds pretended to find Handler's Bartholin's glands before Diaz explained, "We think the vagina is on the outside. I say grab a mirror and play along. Get in there." The actress added, "Learn about it. You're supposed to treat it like the beautiful flower that is, the delicate flower that it is. And you're supposed to nurture it in all the ways that it needs nurturing."

Diaz also explained why she included an excerpt about pubic hair preservation. "Because it's a science book, and since we used to be covered in hair, and now we're not except for a few places, I figure there's a purpose for that hair. So I put some of the purposes for it and I also suggest that no mater how you enjoy grooming it throughout your life—whether it's shave it all off, wax it all off, putt a bulls eye, birthday cake, I don't care—just, girls, think about not taking it all off forever. Permanency means forever. It doesn't come back," the new author said. "You might change your mind in a few years."